JPH1141653A - Radio communication control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain efficient radio communication in a system where the toll of a highway or the like is collected automatically through the use of a radio wave. SOLUTION: This system is provided with plural stationary antennas 10, 11 corresponding to a communication zone forming plural communication zones 20, 21 in a moving direction of a mobile body 1, position detection means 30, 31 that detect that the mobile body 1 specified in the communication zones 20, 21 steps out from the communication zone, and a means that stops assignment of the communication frame to assign the communication zone with respect to the mobile body whose step-out is detected by the position detection means 30, 31. Since a communication frame is not assigned to the mobile body which does not exist in the communication zone, the efficient communication is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention identifies a moving object such as a vehicle that has entered a predetermined spot area, and performs wireless data communication with the moving object to perform automatic charge collection processing. In particular, the present invention relates to a wireless communication control system for collecting data necessary for a mobile communication system, particularly using a communication frame allocated in a time division manner to a moving object passing through two consecutive spot communication zones arranged at a short distance from each other. The present invention relates to a wireless communication control system suitable for efficiently performing wireless communication.

[0002]

2. Description of the Related Art Japanese Patent Laying-Open No. 8-16979 discloses a system for performing wireless communication with a vehicle entering a highway exit zone to automatically collect tolls on the highway. In this prior art, a notice antenna and a tollgate antenna are provided separately for each lane in the exit zone in the vehicle traveling direction, and information about the vehicle is exchanged between the on-vehicle radio and the notice antenna, and the vehicle is mounted. Information on tolls is exchanged between the wireless device and the tollgate antenna.

[0003] In a system that wirelessly exchanges information with a vehicle that has entered a predetermined communication zone, a communication zone is set up in order to avoid radio wave interference with an adjacent system installed in parallel. Narrow the spot. The allowable communication time in the spot communication zone is determined by the length of the communication zone and the moving speed of the vehicle. However, if the spot communication zone is narrowed, it becomes difficult to secure a necessary communication time in one communication zone. For this reason, a second spot communication zone is provided in the traveling direction of the vehicle, information is exchanged with a vehicle that has entered the first spot communication zone, and a vehicle that has left the first spot communication zone is next. By continuing to exchange information with the vehicle when the vehicle enters the second spot communication zone, the problem of allowable communication time can be solved.

[0004]

When a wireless communication is carried out using a plurality of spot communication zones, the control system on the fixed station side does not consider a plurality of communication zones, that is, the same communication control is applied to all communication zones. It is common to do. That is, when a vehicle (mobile body) enters the first communication zone, a request for data link establishment is requested to the fixed station side, and the fixed station side does not consider which communication zone is located in all communication zones and does not recognize the vehicle. And a communication process is started. Communication is established in the communication zone where the vehicle exists, and communication is not established in the communication zone where the vehicle is not present, but the fixed station determines that the communication was successful because communication was established in one communication zone. Assuming, communication for the next process is performed for the vehicle. This can be realized by continuing until a series of processing ends.

However, this control method has the following problems.

[0006] 1) Even in a communication zone where a target movement does not exist, it is necessary to allocate a communication frame for a mobile body that does not exist, which is not only inefficient, but also causes unnecessary radio waves to be transmitted. Absent.

2) Generally, wireless communication with a mobile object is performed by allocating a finite number of time-divided communication frames. In the communication zone where the target mobile does not exist, there is a possibility that another mobile exists, and although the communication frame of the existing mobile is originally assigned, the throughput of the entire system is improved. However, a finite number of communication frames are used due to non-existent mobile communication frames, and there is a case where the existing mobile communication frames cannot be allocated. This phenomenon becomes more pronounced as mobile traffic increases.

3) Generally, communication zones are installed at a certain distance (reuse distance of radio waves) in order to avoid deterioration of communication quality due to interference of radio waves. Accordingly, there is a zone in which communication is impossible between the communication zones, and while the mobile body passes through this zone, all the communication processing performed by the fixed station becomes useless, and the processing load of the system is unnecessarily increased. . In addition, unnecessary radio waves are transmitted similarly to 1), which is not preferable.

[0009] 4) In wireless communication, when communication fails, it is common to perform the recovery by transmitting or receiving the same frame again. Considering the case where the user stays, it is practically impossible to set the number of times of recovery processing in the operation of the system, and there is no means for the system to know that the mobile unit has really failed on the way and communication has been disabled.

An object of the present invention is to provide a wireless communication control system capable of performing efficient communication with high communication quality and without increasing the processing load.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a control system in which a fixed station grasps a communication zone in which a mobile unit exists and allocates a communication frame of the mobile unit only to a communication zone in which the mobile unit exists. Is achieved.

When the mobile enters the first communication zone, it requests the fixed station to establish a data link. The fixed station detects the entry of the mobile unit into the first communication zone based on the request signal, and starts communication processing in the first communication zone. That is, the communication frame is allocated only to the first communication zone, and the communication frame is not allocated to the subsequent second communication zone. When the moving body moves to the end of the first communication zone, the communication zone departure determination is performed based on the position information from the position detecting means. The fixed station determines that communication with the mobile unit in the first communication zone is no longer possible by the departure determination, and ends the communication frame allocation for the mobile unit.

Thereafter, when the mobile enters the second communication zone, a request for establishing a data link is made again. At this time, based on the communication history information in the first communication zone, it is determined whether or not the communication frame for the mobile body in the second communication zone can be allocated and whether or not there is a continuation process. If it is determined that the continuation processing is necessary, the communication frame is allocated and the communication processing is continued. If it is determined that the continuation process is unnecessary, the communication frame is no longer allocated and the departure determination is not performed.

According to such a control method, when a mobile object exists in a communication zone where no mobile object exists or in a zone where the mobile object cannot communicate, a communication frame is not allocated, and another mobile object performs communication in the communication zone. If it exists in the zone, it can be used as a communication frame for another mobile object.

Further, by allocating a communication frame while confirming the presence of a mobile in the communication zone,
The number of times of the recovery process can be set to a finite number that can secure a certain wireless communication quality, and if the recovery process exceeds this number, it is possible to determine that some abnormality has occurred and communication is no longer possible, An optimal wireless communication control system can be constructed, such as improving the reliability of the system, improving the processing performance, and improving the communication efficiency.

[0016]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of the wireless communication control system according to the first embodiment of the present invention. In the wireless communication control system according to the present embodiment, two wireless communication antennas 10 and 11 that are separated from each other in the traveling direction of the moving object 1 are installed, and a communication zone (first communication zone) 20 of the antenna 10 is provided. The antenna 11 is separated from the communication zone (second communication zone) 21 by a short distance so that the radio waves do not interfere with each other. In each of the communication zones 20 and 21, the wireless communication device 2 mounted on the mobile unit 1 and the antennas 10 and 11 perform wireless communication.

The position detecting devices 30, 31 are provided corresponding to the communication zones 20, 21, respectively.
It is detected whether or not the moving object existing within the communication zone 21 has left the communication zone. As the position detection devices 30 and 31, for example, image processing which captures a captured image of a moving object, performs image processing, identifies each moving object from its license plate, and determines whether each moving object has left the communication zone. The system may be configured as a system, or may be configured to receive a radio wave peculiar to the mobile unit from the wireless device 2 mounted on the mobile unit 1 and determine the separation of the mobile unit from the communication zone by triangulation.

The wireless communication control device 40 according to the present embodiment
Is a wireless communication unit 41 connected to the antennas 10 and 11
A wireless communication control unit 42, an inter-device communication unit 43 connected to the position detection devices 30 and 31, a communication zone departure determination unit 44 that determines whether or not a mobile body has departed from each communication zone, The shared storage medium 45 is connected to these 41, 42, 43, and 44 and performs a function of exchanging information between the units. Between the mobile unit and the antennas 10 and 11, wireless communication is performed using the communication frame allocated by the wireless communication control unit 42 among the time-divided communication frames, and a plurality of communication frames are provided in the same communication zone. Even when a mobile object exists, wireless communication with each mobile object is possible at the same time. In the communication zones 20 and 21, communication is performed using the same radio frequency.

The mobile unit 1 transmits / receives radio waves using the mounted radio 2 in the communication zone 20 of the radio communication antenna 10 and exchanges data with the radio communication control device 40. . The position detection device 30 sends the identifier of the mobile unit 1, the detected position, and the identifier of the communication zone 20 to the inter-device communication unit 43, writes the data received by the inter-device communication unit 43 to the shared storage medium 45, and leaves the communication zone. The determination unit 44 acquires these data by searching the shared storage medium 45.

The communication zone departure determination unit 44 determines whether the mobile unit 1 has left the communication zone 20 based on the position of the mobile unit 1 and the identifier of the communication zone 20, and determines that the mobile unit 1 has left the communication zone 20. Then, the leaving notification including the identifier of the mobile unit 1 and the identifier of the communication zone 20 is written in the shared storage medium 45.

The wireless communication control unit 42 includes a shared storage medium 45
, When the notification of the departure of the mobile unit 1 is received, the allocation of the communication frame to the mobile unit 1 in the communication zone 20 is stopped, and the information communication history information indicating how far the communication process with the mobile unit 1 has been completed is shared. It is stored in the storage medium 45.

When the mobile unit 1 enters the communication zone 21 of the wireless communication antenna 11 after leaving the communication zone 20, the wireless communication control unit 42 moves in the data link establishment process with the mobile unit 1. Get the identifier of body 1. The wireless communication control unit 42 uses the identifier to search the shared storage medium 45 to know information communication history information indicating how far the mobile unit 1 has completed the communication processing in the communication zone 20. Based on this information, the wireless communication control unit 42 starts a communication process between the mobile unit 1 and the communication process that has been completed in the communication zone 20.

As described above, by knowing that the mobile unit 1 has left the communication zone 20, the radio communication control device 40
This eliminates the need to perform wireless communication with the mobile unit 1 without expectation of successful communication. Further, the wireless communication control device 40 can take over the communication processing in the communication zone 20 in the communication zone 21. Therefore, continuation of processing between communication zones can be optimally and efficiently performed.

FIG. 2 is a flowchart showing a processing procedure performed by the wireless communication control unit 42 in the wireless communication control device 40. The wireless communication control unit 42 performs processing according to this flowchart for each mobile unit and each communication zone. .

First, a data link establishment process (step 1) between the mobile unit and the radio communication controller is performed. That is, in order for the wireless communication control device to start wireless communication with the mobile unit, negotiation for establishing a data link, such as receiving an identifier of the mobile unit from the mobile unit, is performed.

In the next mobile communication history information registration judgment processing (step 2), it is checked whether or not the mobile radio equipment which has established the data link has already performed the radio communication processing in another communication zone. . If the wireless communication process has not been performed, the process jumps to step 4.

If wireless communication processing has already been performed,
Proceed to step 3 to take over this wireless communication process.
The communication history information of the mobile unit (identifier of the mobile unit, information on how far communication with the mobile unit has been performed) is fetched from the shared storage medium, and the process proceeds to step 4.

In the mobile communication zone leaving information presence / absence determination processing in step 4, it is determined whether or not the mobile body is present in the communication zone. This determination is made based on the departure information from the communication zone departure determination unit, that is, the identifier of the departed mobile unit and whether or not the identifier of the departed communication zone exists in the shared storage medium. This communication zone leaving information presence / absence determination processing includes:
It is performed before the execution of this sequence for each wireless communication sequence with the mobile unit.

If there is no moving body leaving information, the process proceeds to step 5, where a communication frame is allocated to the moving body. If there is information on the leaving of the moving body, the process proceeds to step 6, where the communication with the moving body is not performed, and the communication history of the moving body is stored in the shared storage medium.

FIG. 3 is a flowchart showing a processing procedure performed by the communication zone leaving determination section 44. First, the identifier of the communication zone in which the position information of the mobile unit is detected, the identifier of the mobile unit, and the position are received via the shared storage medium 45 (step 10). Next, it is determined based on the size of the communication zone indicated by the identifier of the communication zone and the position of the mobile object whether or not the mobile is in the communication zone (step 11). If the mobile unit is within the communication zone, the process ends. If the mobile unit has left the communication zone, the release information of the mobile unit (the identifier of the mobile unit and the communication zone from which the mobile unit has left). Is stored in the shared storage medium (step 12), and the process ends.

FIG. 4 is a configuration diagram of a wireless communication control system according to a second embodiment of the present invention. The wireless communication control system according to the present embodiment includes a wireless communication control device 40 (the internal configuration is the same as that of FIG. 1) corresponding to the antenna 10 and another wireless communication control device 70 corresponding to the antenna 11.
(The internal configurations of the wireless communication control devices 40 and 70 are the same, and 71 to 71 are the same as the internal configurations 41 to 45.
The reference numeral 75 is assigned and the description is omitted. ), The inter-device communication unit 43 of the control device 40 and the inter-device communication unit 73 of the control device 70 are connected via the shared transmission line 60, and the disconnection notification and the like detected by the control device 40 are transmitted to the shared transmission line 60. Is transmitted to the control device 70 side via the. still,
In this embodiment, the wireless communication control device is provided for two antennas. However, when three or more communication zones are provided and the wireless communication control devices are provided for each antenna, each wireless communication control device is provided. The communication unit between the devices is shared transmission line 6
0 may be connected.

The operation of the wireless communication control device 40 is the same as that described with reference to FIG. 1, and communication history information and the like in the communication zone 20 of the mobile unit 1 are written in the shared storage medium 45. The inter-device communication unit 43 reads the communication history information of the mobile unit 1 from the shared storage medium 45 and transmits the information to the wireless communication control device 70 via the shared transmission path 60. The transmission of the communication history information may be point communication to the adjacent wireless communication control device 70 or broadcast communication to all the wireless communication control devices connected to the shared transmission path 60. The transmitted communication history information is received by the inter-device communication unit in the wireless communication control device of the other party, and stored in the shared storage medium in the own wireless communication control device.

When the mobile unit 1 enters the next communication zone 21, the wireless communication control unit 72 obtains an identifier of the mobile unit 1 in a data link establishment process with the mobile unit 1. Wireless communication control unit 72
Searches the shared storage medium 75 using this identifier to know information about how far the mobile unit 1 has completed the communication processing in the communication zone 20. Then, based on this information, the wireless communication control unit 72 continues the communication processing following the communication processing performed in the communication zone 20 in the communication zone 21.

In this embodiment, similarly to the embodiment shown in FIG. 1, there is no need to perform wireless communication with no possibility of successful communication with the mobile unit 1, and the communication zone 21 takes over the communication processing in the communication zone 20. Thus, continuation of processing between communication zones can be optimally and efficiently performed without allocating useless communication frames.

FIG. 5 is a configuration diagram of a wireless communication control system according to a third embodiment of the present invention. The wireless communication control device 40 used in the wireless communication control system according to the present embodiment includes:
A wireless communication unit 41, a wireless communication control unit 42, a communication zone departure determination unit 44, and a shared storage medium 4 connected thereto.
And the wireless communication unit 41 includes two antennas 1
0 and 11 are connected to the communication zone 20 of the antenna 10.
And the communication zone 21 of the antenna 11 are provided to be separated by a short distance. A pair of position detection antennas 16 and 17 arranged on the left and right sides in the width direction of the moving body 1 are connected to the wireless communication device 2 mounted on the moving body 1, and radio waves transmitted from the antenna 10 (or 11). The angles of radio waves 33 and 34 spread to the left and right of 30
7 for receiving.

The mobile unit 1 transmits / receives radio waves in the communication zone 20 and exchanges data with the wireless communication control unit 40. A pair of moving object position detecting antennas 1
The wireless communication device 2 having the antennas 6 and 17 receives the radio wave transmitted from the antenna 10 as a fixed station,
The position of the mobile unit 1 is calculated from the phase difference between the angles of entry of the radio waves 33 and 34 received by the radio waves 6 and 17, the position is set in the transmission data, and transmitted to the wireless communication control device 40.

The wireless communication unit 41 of the wireless communication control device 40
Is the identifier and location information of the mobile unit 1 and the communication zone 20
Is received and written in the shared storage medium 45, and the communication zone departure determination unit 44 captures the information. The communication zone departure determination unit 44 determines whether the mobile unit 1 has left the communication zone 20 based on the position of the mobile unit 1 and the identifier of the communication zone 20.
The leaving notification information including the identifier of the mobile unit 1 and the identifier of the communication zone 20 is written in the shared storage medium 45. The wireless communication control unit 42 reads this leaving notification information, and when it knows the leaving of the mobile unit 1, stops the assignment of the communication frame to the mobile unit 1 in the communication zone 20 and completes the communication processing with the mobile unit 1. The information of whether the operation has been performed is stored in the shared storage medium 45.

When the mobile unit 1 enters the communication zone 21,
The wireless communication control unit 42 obtains the identifier of the mobile unit 1 in the data link establishment process with the mobile unit 1. By searching the shared storage medium 45 using this identifier, the wireless communication control unit 42 knows information about how far the mobile unit 1 has completed the communication processing in the communication zone 20. Then, based on this information, the wireless communication control unit 42 starts the continuation of the communication processing in the communication zone 21.

According to the present embodiment, similarly to the embodiment of FIGS. 1 and 4, there is no need to perform wireless communication with no possibility of successful communication with the mobile unit 1.
Can take over the communication processing in the communication zone 20 in the communication zone 21. Therefore, in the wireless communication system of the present invention, it is possible to optimally and efficiently continue processing between communication areas.

[0040]

According to the present invention, a moving object such as a vehicle that has entered a predetermined spot area is identified, and wireless data communication is performed with the moving object to perform an automatic charge collection process. In a wireless communication control system that collects data necessary for communication, efficient communication can be performed with high communication quality and without increasing the processing load.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a wireless communication control system according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating a processing procedure of a wireless communication control unit illustrated in FIG. 1;

FIG. 3 is a flowchart illustrating a processing procedure of a communication zone departure determination unit illustrated in FIG. 1;

FIG. 4 is a configuration diagram of a wireless communication control system according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram of a wireless communication control system according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Mobile body, 2 ... Wireless communication equipment mounted on a mobile body, 10, 11 ...
Antennas (fixed station side), 20, 21 spot communication zone, 30, 31 position detecting device, 40, 70 wireless communication control device, 41, 71 wireless communication unit, 42, 72 wireless communication control unit, 43 , 73 ... Inter-device communication unit, 44, 74 ...
Communication zone departure determination unit, 45, 75 ... shared storage medium, 6
0: Shared transmission path.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takeshi Hiroki 5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture Inside the Omika Plant, Hitachi, Ltd. (72) Inventor Takayuki Iino 5-chome, Omika-cho, Hitachi City, Ibaraki Prefecture No. 1 Inside Hitachi, Ltd. Omika Plant (72) Inventor Kazunori Takahashi 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd. Hitachi Research Laboratory (72) Inventor Teruo Takagi Omika, Hitachi City, Ibaraki Prefecture 5-2-1, Machi, Hitachi Information & Control Systems Co., Ltd.

Claims (4)

[Claims] The present invention relates to a TDMA (Time Division Multiple Multiple Access) between a mobile unit and a mobile unit that has entered a communication zone.
In a wireless communication control system for performing wireless data communication using a communication frame allocated by the (Access) method, a plurality of the communication zones are arranged at a distance from each other and the mobile station continuously passes through the communication zones. A wireless communication control system comprising: means for allocating, for each of the communication zones, the communication frame for performing wireless communication with the mobile body when performing data communication according to (1). 2. A plurality of fixed station antennas corresponding to a communication zone forming a plurality of communication zones in a moving direction of the moving object, and a moving object provided for each communication zone and specified in the communication zone defines the communication zone. Wireless communication control comprising: a position detecting means for detecting the separation; and a means for stopping the allocation of a communication frame allocated in the communication zone to the mobile object from which the separation has been detected by the position detecting means. system. 3. The mobile communication system according to claim 1, wherein, if necessary wireless communication is not completed in the first communication zone, a communication history of the mobile unit in the first communication zone is referred to. A wireless communication control system comprising means for performing subsequent wireless communication in a communication zone. 4. A communication device according to claim 1, further comprising means for judging a communication error based on the number of times of recovery processing for the mobile unit when a communication error occurs during communication in any communication zone. A wireless communication control system characterized by the above-mentioned.